The Influence of Selected Risk Factors on the Hearing Threshold Level of Noise Exposed Employees

Abstract

The aim of the study was to evaluate the combined effect of noise exposure and additional risk factors on permanent hearing threshold shift. Three additional risk factors were: exposure to organic solvents, smoking and elevated blood pressure.The data on exposure and health status of employees were collected in 24 factories. The study group comprised of 3741 noise male exposed workers of: mean age 39±8 years, mean tenure 16±7 years and L EX,8h = 86 ± 5 dB. For each subject, hearing level was measured with pure tone audiometry, blood pressure and noise exposure were assessed from the records of local occupational health care and obligatory noise measurements performed by employers. Smoking and solvent exposure were assessed with questionnaire. The study group was divided into subgroups with respect to the considered risk factors. In the analysis, the distribution of hearing level of each subgroup was compared to the predicted one which the standard calculation method described in ISO 1999ISO :1990. For each of the considered risk factors, the difference between measured and calculated hearing level distribution was used to establish, by the least square method, a noise dose related correction square function for the standard method. The considered risk factors: solvent exposure, smoking and elevated blood pressure combined with noise exposure, may increase degree of hearing loss.

Noise-Induced Hearing Loss in Professional Orchestral Musicians

“…It is worth to underline that aforesaid standard specifies the method for prediction of NIHL after given exposure to noise based on four parameters: age, gender, noise exposure level and duration of noise exposure (in years). However, it does not take into consideration risk factors other than occupational noise, such as exposure to noise beyond workplace (e.g., leisure noise, noise exposure during compulsory military service), co-exposure to certain chemicals (organic solvents and heavy metals), vibrations, and several individual factors and NIHL, including smoking, elevated blood pressure, cholesterol and skin pigmentation (Toppila et al, 2001, Pyykko et al, 2007Dudarewicz et al, 2010). It does not discuss the protective effects of hearing protective devices, either.…”

“…The study group comprised musicians playing violin (37), viola (13), cello (10), oboe (10), flute (8), horn (8), trombone (7), bassoon (7), clarinet (6), trumpet (5), double bass (4), percussion (3), tuba (2) and other instruments (4).…”

Frequency of the Audiometric Notch Following Excessive Noise Exposure

“…The NIHL and age-related hearing loss often coexist in the same ear, however, the conditions under which these forms of hearing loss interact remain poorly understood (Kujawa, Liberman, 2006). Presbyacusis and noise exposure are strongly correlated, and presbyacusis may even overrule the effect of noise in hearing loss (Dudarewicz et al, 2010).…”

Evaluation of Sound Exposure and Risk of Hearing Impairment in Orchestral Musicians

“…This study calculated percentages of subjects with HTLAN exceeding the limit value of 25,35 or 45 dB and the risk of hearing loss due to noise alone for various groups of players (separately for females and males), for the accepted hypothetical period of professional exposure (7-42 years) and age (25-60 years) in 5-year steps. These calculations were performed on the basis of L EX,w,10 ; L EX,w,50 and L EX,w,90 that were established for the various groups of players.…”

“…On the other hand, the percentage of females and males with mean HTLAN at frequencies of 2, 3, 4 kHz above 35 dB remained within the range of 4-29% and 18-44%, respectively ( [4,8]. Moreover, that standard does not discuss risk factors other than occupational noise, such as exposure to noise beyond workplace (e.g., leisure noise, noise exposure during compulsory military service), co-exposure to certain chemicals (organic solvents and heavy metals), vibrations, and several individual factors and NIHL, including smoking, elevated blood pressure, cholesterol, skin pigmentation, gender and age [23,24,25]. It does not discuss the protective effects of hearing protective devices, either.…”